One particular application of the invention is concerned with machines for use in the retreading of tyres. These machines are often referred to as buffing machines and include a tool which removes rubber from the tyre prior to the retreading procedure. The tool maybe in the form of a drum having cutting teeth or blades arranged on the outer surface thereof. The drum is mounted for rotation about its central axis. Such a tool is often referred to as a rasp.
When the rubber is removed from the tyre by the buffing machine the removed rubber may be in the form of long strips, large chunks, medium particles, small crumb size and fine dust. Rubber is very abrasive and as a result the blades on the tool can become blunt very quickly. During the buffing process the blades not only cut into the rubber but also impact with any foreign objects that may be embedded therein. The blades are thin and designed to cut through rubber but not to impact and grind foreign objects such as glass, nails, stones and the like embedded in the surface of the rubber. These objects when dislodged from the tyre are quite dangerous to the operator and it is desired that the objects are directed to an extraction system for drawing the removed rubber and foreign objects away from the operator.
Because of the high wear on the blades, they are designed to be able to cut in both directions of rotation and as such it is necessary to remove the tool from its mounting so that it can be turned so that both sides of the cutting blades can be used. This can be a tedious and time consuming operation.